Chair construction



Dec. l0, 1946. T. w. Foo-rE CHAIR CONSTRUCTION Filed Nov. 1e, 1942 HG. j

BY 77/0Mns W Hoor-5 M Mfnf Toe/vsrs y Patented Dec. l0, 1946 UNlTEDSTATES PATENT ori-"ICE CONSTRUC'HQN n Themas W. Fette, East cleveland,ohie l Application November 16, 1942, Serial N 0. 465,646

3 Claims. (Cl. 155-95) 1 2 This invention relates" ltp a chairconstruction those portions of the chair construction which and moreparticularly to that typepf chair c onare shown in section in Fig. l buton a larger scale struction known as a ASwivel chair. and illustratesthe relationship of the parts when An object of the invention is toprovide a the adjusting and supporting shaft is "loclred swivel chairconstruction which is simple, pos- 5 against al1 movements and thespider is free to `sesses stability and provides for ready adjustrotateo n the shaft. ment over a Wide range. Fig. 3 is a fragmentary sectionalview taken Another object is to provide in a chair consubstantially online 3-31 of Fig. 2, loolging in struction improved means for adjustingthe chair the direction of the arrows, and seat relative to the chairbase. l Fig. l is a fragmentary sectional view taken A further object isto provide in a swivel chair substantially on line 4 4, of Fig. 2looking in the construction improved supporting means for the directionof the arrOW$. spider which carries the chair seat and which The swivelChair COIlStIllCtOnllllStrated inthe means permits free rotation of thespider and drawing comprises a Chair seat and back I0., chair seat witha minimum amount of friction l5 indicated in Fig. 1 by dash lines, andwhich seat between the spider and its support and including iS attachedby means of securing screws or other provision for adequately takingboth the end and Suitable means (not Shown) t0 the arms of the lateraltllrtlStS @Xerted by the spider on its spider Il. The spider `Il may beconstructed to support, provide tilting movement of the chair seat rela-Another object is to provide in a, chair con- 4tive to the chair base,or it may be constructed so struction improved means fer adjusting theshaft that the ltheir Seat has n0 tilting movement as which connects thebase of the chair with the Will be Well understood in the art. Thespderll spider that carries the ,Chair seat and which iS adl'ustably andoperatively connected with the means enables the shaft to be locked inadjusted base ll2 by means 0f an adjustable raising and position andfirmly held against lateral move: lowering supporting shaft later to bereferred to.

ments with respect to the Chair base, 4thus im- The three main portionsor sub-assemblies of the parting stability to the chair. swivel chairconstruction as just referred t are Another object is to provide aswivel chair usually employed in chairs of this type andbroadconstruction which enables the ychair to be built ly are wellunderstood in the art. substantially entirely from materials other than3Q The Spider ll SllOWn herein COmprseS a pair of metals such, foreXa'mple, as wood `or plastic masupporting arms I3 (Only One of sucharms being terials and which construction is so designed shown in thedrawing) and which arms are that any expansion or contraction talgngplace connected intermediate .their ends by a transirr the adjustable orrelative movable'parts of Versely extending connecting member I4 whichthe construction willnotinterfere with the proper on its lower side isprovided with a downadjustment and movements of the chair. wardlyprojecting vboss t5 illustrated herein as A further object is to providea swivel chair being of substantially conical cong'uration andconstruction wherein the chair spider which carngral .with the memberI4, 'although it will ries the seat can be adjusted relative to thechair be understood that said boss, if desired,l couldbe base `over awide range 0f very fine' adjustments 40 separate from saidmember I4 andsecured thereand which construction requires a minimum to. The spider Ilmay be constructed of' any amount of machining and other nishingoperdesired material, that is, it could be constructed ations in itsmanufacture. of metal, if such material were desired and avail-Furtherand additional objects and advantages able, or it could be formedof wood or some suitnot hereinbefore specied will becm'e apparent e?,able plastic material. In this connection if the during the detaileddescription which is 'to' follow Spider were formed 0f plastic materialit Would of an embodiment of the invention. Referring lend itselfreadily to being produced by molding to the accompanying drawingillustrating said operations and would thus eliminate thenecesemb'odimenrt of the invention, r sity of vmachining and finishingthe spider there- Fig. l is a View,` partly in elevation and partly bymaterially reducing Vthe cost of its manufacin section, of a swivelchair with the base and ture. spider of the chair shown in full linesand the The connecting member i4 and the -boss I5 of chair seatsupported by the spider indicated by the spider are provided withacylindrical cendash lines; the sectional portions of this view iltrallydisposed and upwardly extending'. bore in lustrating the relationship ofthe parts when the the base or upper end of .which is mounted a ringadjusting and supporting shaft is free te be rol (shown in elevation" inFig. 1 and in section tated for adjustment purposes, while the spider inFig. 2) which may be formed of any suitable is locked to the shaftagainst rotation relative material, although a hard fiber ring can beadthereto. vantageously employed in lthis relationship. A

Fig. 2 is a fragmentary sectional view showing 60 sleeve kbushng I1 islmounted and suitably secured in the bore with a tight engagement thereinand extends from the lower end of the boss I5 upwardly into contact withthe ring I3, and holds the latter in place. The sleeve bushing may beformed of any suitable desirable and available material, but like thering I5, fiber material may advantageously be used to form the bushing.A locking screw I9 is threadedly mounted in the connecting member I4 andpasses through the sleeve bushing I1 into the recess and perpendicularlyto the longitudinal axis of the latter and said screw at its outer endis provided with an operating head so that it can be readily adjusted tovarious positions.

The base I2 of the chair construction includes the usual legs 2l whichconverge at their inner ends and are interconnected by suitableinterlocking mortised and tenoned connections forming no part of thepresent invention. The central portion of the base where the convergentlegs are interconnected may be termed a table portion 22 and throughwhich portion extends the adjusting and supporting shaft, later to bereferred to. The table portion 22 of the base is provided with acylindrical bore extending vertically and centrally therethrough. Thetable portion also adjacent the upper end of the bore is provided with alongitudinally extending recess `23 come municating with the bore andreaching from the top of the table 22 vertically downwardly a shortdistance. vA smooth sleeve bushing 24 is mounted in the bore in thetable 22 and has a close t therein and adjacent its upper end isprovided with a slot which registers with the recess 23 for a purposelater to be explained. The sleeve bushing 24 may be formed of anydesired and available material, although a fiber bushing can beadvantageously used for this purpose. The bushing is not threadedinteriorly and has a smooth interior bore.

A block 25 is mounted in the recess 23 and extends through the slot inthe sleeve bushing 24 and into the bore of the latter. The block 25 canmove in the recess 23 and in the slot in the bushing 24 laterally andperpendicularly to the longitudinal axis of the bushing for a purposewhich will soon become apparent. The block 25 is held against movementin a direction longitudinally of the bushing 24 by its engagement withthe lower end of the recess 23 and the lower end of the slot in thebushing 24 and by a plate 25 secured to the upper side of the table 22of the base and provided with a central opening coinciding with the borethrough the bushing 24 and of the same diameter. The block 25 is alsoheld against sidewise movement by the side walls of the recess.

The block 25 is assembled in the chair base before the plate 26 issecured in position by merely inserting the block downwardly into therecess 23' and the slot formed in the bushing 24. A plate 21 similar tothe plate 26 is secured to the underside of the table 22 of the chairbase, as clearly indicated in Figs. 1 and 2, and although said plates 2Oand 21 may be of any suitable material they can advantageously be formedof fiber, composition or plastic material.

The inner end of the block 25 within the bushing 24 is arcuate in shape,with the curvature thereof having the same radius as the root circle ofthe threaded portion of the adjusting and supporting shaft later to bereferred to. This inner end of the block 25 is provided with a number ofscrew threads 28 of the same lead and pitch as are the screw threads ofthe threaded portion cf the adjusting and supporting shaft later to bereferred to. The block 25 may be moved or adjusted within the recess 23and the slot in the bushing 24 and perpendicularly with respect to theaxis of the latter by means of an adjusting and holding screw 29 whichis threadedly carried by the table 22 and has its inner end projectinginto the recess 23 and engaging the outer flat side of the block 25, asclearly indicated in Figs. l, 2 and 4. The block 25 may be formed ofvarious suitable and available materials but hard fiber materialcan beadvantageously employed for this purpose. The outer end of the.adjusting screw 29 is provided with an operating head 30 to facilitatethe turning of the screw.

The adjusting and connecting shaft which operatively interconnects thechair base I2 and the spider II and supports the latter comprises anupper end portion 3| which is smooth and projects into the sleevebushing Il carried by the connecting member I4 and boss I5 of thespider. The smooth portion 3| of the shaft is of less diameter than theinternal diameter of the bushing in order to provide substantialclearance between the shaft and bushing.

The shaft at its upper end beyond the smooth portion 3| is provided witha reduced portion 3Ia. A bushing 32 is secured on the reduced portion3|a and has at its lower end a radial flange 33 which bears against theshoulder formed by the end of the portion 3|. The bushing 32 and flange33 may be formed integral with each other or they may be formed with theflange 33 in the nature of a ring separate from the bushing. The bushing32 and flange 33 may be formed of any suitable and available materialbut preferably they can be formed of hard fiber. The bushing 32rotatably interts the ring I6 while the flange 33 engages the lower endof said ring, for a purpose which will become apparent later. The smoothportion 3| of the shaft has tightly fixed thereon at the lower end ofsaid portion a relatively short bushing 34 which rotatably interfits theinterior of the lower end of the sleeve bushing This bushing 34 is shownin the drawing as a member separate from the shaft, but it will beunderstood that the shaft could be so shaped as to have a portionequivalent to the bushing and formed integral with the shaft. Thebushing 34 may be formed of the same material as the shaft or it can beformed of any suitable and available material as, for example, it can beformed of fiber.

From the description thus far set forth it will be seen that the spideris supported on the portion 3| of the shaft by the engagement of thebushing 32 and flange 33 with the ring bushing I6 and that suchengagement constitutes a bearing support for the 'spider on the shaftand which bearing support takes both the end and lateral thrusts exertedby the spider on the shaft. It will also be noted that the bushing 34which rotatably nterfits the lower end of the sleeve bushing Il preventslateral movement of the spider with respect to the shaft.

It will also'be noted that the spider can freely rotate relative to theshaft with a minimum amount of friction since only the bushing 32 and'flange 33 and the bushing 34 contact the ring I6 and bushing Il. That isthe shaft and spider have only a minimum area contact.

The inner end of the screw I9 underlies the flange 33. The screw I9 maybe screwed inwardly to tightly engage the shaft with a clamping actionand lock the spider and shaft against relative rotation, as indicated inFig. 1.

The screw I9 may be backed off slightly from the clamping engagement ofits inner end with the shaft and at such time the 'spider can freelyrotate relative to the shaft but is held against endwise movementrelative thereto by the flange 33 engaging the ring I6 and the screw I9.

The adjusting and supporting shaft below the smooth portion 3| and thebushing 34 has a portion 36 that is provided with screw threads 31 andwhich threads, as already stated, have the same lead and pitch as thethreads 28 of the block 25, while the root circles of the threads 28 andthe threads 3l are of the same radii. The external diameter of theportion 36, including the threads 31, is less than the internal diameterof the sleeve bushing 24, wherefore there is clearance between thethreaded portion of the shaft and said bushing.

In assembling the chair, the lower end of the threaded portion of theshaft is passed through the opening in the plate 2S and the shaft thenrotated to cause the threads 31 to screw into the threads 28 of theblock 25 until the shaft extends sufciently far into the bushing 24. Theshaft can be locked against both rotative and lateral movement in thebushing 2li by tightening the screw 29 to force the lblock 25 tightlyagainst the shaft and wedge or push the latter tightly against the wallof the bushing, as indicated in Figs. 2 and 4. When the block 25 is thustightly engaged with the shaft the teeth of the block wedginglyinterlock with the teeth 0f the shaft to hold the shaft againstrotation, and since the shaft at one side is pressed firmly against thebushing 24 said shaft cannot move laterally with respect to the bushingand therefore stability is imparted to the chair.

The adjusting and supporting shaft may be formed of any suitablematerial, but since the shaft has only a limited area Contact with thebushing il and the spider and there is a clearance between the threadedportion of the shaft and the bushing 24 said shaft can be formed ofwood, if desired, since expansion and contraction of the shaft becauseof humidity and temperature changes would be immaterial and would notcause any binding of the shaft in the parts into which r it extends.

The shaft sho-wn herein for purposes of illustration is a wooden shaftwhich may be impregnated with oil or otherwise treated.

In Fig. 1 the screw I9 has been turned into clamping engagement with theadjusting and supporting shaft to loci: the spider II against rotationrelative to the shaft. Al'so in Fig. 1 the screw 29 has been backed olfso that the shaft is not clamped against the bushing 2li and is free torotate therein. This is the arrangement that is effected when it isdesired to adjust the Vertical height of the chair seat Iii. At thistime the user of the chair by revolving the chair seat can rotate thespider I I and the supporting shaft lwhich is locked thereto, with theresult that the threaded portion of the shaft screws downwardly orupwardly in the bushing 24 of the chair base with the threaded block 25acting as a fixed nut for this purpose.

Inasmuch as the block 25 is located at the upper end of the bushing 24the adjustment of the shaft with respect to the bushing 24 may be over awide range. This adjustment since it is brought about by the action ofthe threaded portion of the shaft with respect to the block 25 is a fineadjustment, as distinguished from the course adjustments obtainable inchairs of this type employing a shaft having spaced holes and a pin toengage selectively in one or another of said holes.

When the user has adjusted the height of the chair seat to that desiredthe screw 29 is turned from the position shown in Fig. l to that shownin Fig. 2 to push the block 25 inwardly and force the threaded portionof the shaft against the bushing 24, as indicated in Figs. 2 and 4. Whenthis has been done the shaft is locked against rotation and againstlateral movement, wherefore wobbling of the chair seat relative to thebase is eliminated. The user now backs off the screw I9 from theposition shown in Fig. 1 to that shown in Fig. 2 to release the lockingengagement of the screw with the shaft, whereupon the chair seat II) andspider II can rotate freely and with a minimum of friction relative tothe shaft but are held against relative endwise movement by the flange33 engaging the ring I6 and the screw I9.

From the foregoing description it will have been seen that the presentinvention provides a chair construction which is simple, efficient andcan be readily assembled. Furthermore, the parts are so constructed andinterrelated that they need not be formed of metal but can beconstructed of plastics or of wood, since sufficient clearance isprovided between the operative parts to prevent locking or bindingthereof if such parts should expand because of atmospheric conditions.

Although a preferred embodiment of the invention has been illustratedand described herein, it should be understood that the invention issusceptible of various modifications and adaptations within the scope ofthe appended claims.

Having thus described my invention, I claim:

1. In a chair construction, a spider having a portion for supporting aseat and a portion provided with a downwardly facing cylindrical boretherein, a ring bushing secured in the upper end of said bore, a sleevebushing secured in said bore with its upper end in contact with saidring bushing, a shaft extending into said sleeve bushing and of lessdiameter than the interior of the latter, a reduced portion extendingfrom the upper end of said shaft, and a bushing secured on said reducedportion and rotatably engaging within said ring bushing and provided atits lower end with a radially extending flange engaging the lower sideof said ring bushing.

2. A chair construction as defined in claim 1 and wherein said secondnamed portion of said spider is provided with adjustable means extendinginto said bore and cooperating with said flange and adapted to preventat all times relative axial movement between said shaft and said spider,said adjustable means also acting upon adjustment to tightly engage saidshaft to lock said spider and said shaft together against any relativemovement.

3. A chair construction as defined in claim 1 and wherein said shaft isprovided remote from its upper end with -means rotatably intertting overa limited area the interior of said sleeve bushing.

THOMAS W. FOOTE.

